The stepwise addition of increasing amounts of Au(PPh3)Cl to [HRu4(CO)12]3− (1) results in the sequential formation of [HRu4(CO)12(AuPPh3)]2− (2), [HRu4(CO)12(AuPPh3)2]− (3), and HRu4(CO)12(AuPPh3)3 (4). Alternatively, 4 can be obtained upon addition of HBF4·Et2O (two mole equivalents) to 3. Further addition of acid to 3 (three mole equivalents) results in the formation of the tetra-aurated cluster Ru4(CO)12(AuPPh3)4 (5). Compounds 2-5 have been characterized by IR, 1H and 31P{1H} NMR spectroscopies. Moreover, the molecular structures of 3-5 have been determined by single crystal X-ray diffraction as [NEt4][3]·2CH2Cl2, 4-b·2CH2Cl2, 4-a, 5·0.5CH2Cl2·solv, and 5·solv crystalline solids. Two different isomers of 4, that is 4-a and 4-b, have been crystallographically characterized and their rapid interconversion in solution was studied by variable temperature 1H and 31P{1H} NMR spectroscopies. Weak aurophilic Au⋯Au contacts have been detected in the solid state structures of 3-5. Computational studies have been performed in order to elucidate bonding and isomerism, as well as to predict the possible structure of the elusive species 2.
Peraurated ruthenium hydride carbonyl clusters: aurophilicity, isolobal analogy, structural isomerism, and fluxionality
Cesari, C.;Bortoluzzi, M.;
2024-01-01
Abstract
The stepwise addition of increasing amounts of Au(PPh3)Cl to [HRu4(CO)12]3− (1) results in the sequential formation of [HRu4(CO)12(AuPPh3)]2− (2), [HRu4(CO)12(AuPPh3)2]− (3), and HRu4(CO)12(AuPPh3)3 (4). Alternatively, 4 can be obtained upon addition of HBF4·Et2O (two mole equivalents) to 3. Further addition of acid to 3 (three mole equivalents) results in the formation of the tetra-aurated cluster Ru4(CO)12(AuPPh3)4 (5). Compounds 2-5 have been characterized by IR, 1H and 31P{1H} NMR spectroscopies. Moreover, the molecular structures of 3-5 have been determined by single crystal X-ray diffraction as [NEt4][3]·2CH2Cl2, 4-b·2CH2Cl2, 4-a, 5·0.5CH2Cl2·solv, and 5·solv crystalline solids. Two different isomers of 4, that is 4-a and 4-b, have been crystallographically characterized and their rapid interconversion in solution was studied by variable temperature 1H and 31P{1H} NMR spectroscopies. Weak aurophilic Au⋯Au contacts have been detected in the solid state structures of 3-5. Computational studies have been performed in order to elucidate bonding and isomerism, as well as to predict the possible structure of the elusive species 2.I documenti in ARCA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.